The present invention relates to apparatus for transplanting seedlings from a propagating and growing tray directly into a prepared ground planting position.
Transplants comprising a plant growing in a discrete and separate mass of growing medium, known as a plug or more simply as plant seedlings, have traditionally been planted by hand or by means of a semi-automatic machine which generally performs one or more of the following functions:
(i) A rotating set of cups receive a manually selected and placed plant.
(ii) The plant cup mechanically opens and drops the plant via free fall to the ground height.
(iii) A mechanical pushing mechanism pushes the transplant out of the rear of the soil opening shoe.
(iv) A variety of machines variously drop plants into a belt with finger wires to assist in guiding the plant tops in an attempt to hold the plant vertical.
(v) Other mechanical transplanting mechanisms remove every plug regardless of whether or not a plug contains a living plant which causes gaps in the plant spacing in the field.
In all of the manual and automatic transplanters described there is:
(a) A continuous movement of plugs from the container tray to the ground with no provision for gapping up that is a separate zone able to move plants at different speeds to another zone with the ability to change one zone speed from stationary to very high speed and transfer the seedling to another zone.
(b) No provision for separate areas of plant storage or provision for sorting plugs not containing plants from plugs with plants.
It is accepted that 10-15% of tray cells in a nursery tray of seedlings will not contain a live seedling suitable for transplanting into the field. This will result in a market gardener or the like having to have additional workers to hand plant seedlings in the missing gaps. A more difficult problem may result if the machine not only leaves gaps but also plants seedlings too close together which require workers to manually dig out and replant such seedlings. In the case of celery, for example, 45,000 seedlings are planted per acre and 15% missing live seedlings in the trays amounts to 6750 gaps or misses per acre that have to be manually planted. In Australian Patent Application No. 460909/93 there is disclosed an arrangement which will allow seedlings to be transplanted from trays into a field position with their spacing substantially uniform, however, this arrangement, while working satisfactorily is relatively complicated and therefore expensive to produce. Field planting machinery of this general type also desirably requires a number of other capabilities including the ability for adjacent rows of planted seedlings to be closely adjacent one another and in some cases down to eight inch row centres and that it be capable of simple connection to and operation from conventional tractors commonly used by nursery men and market gardeners.
The current practice of mechanically pushing a plant out of the soil opening shoe is reliant on the plants dropping vertically over a long distance and arriving at the correct time to coincide with the plant pushing mechanism and then pushing only to the shoe edge. This results in very variable planting in terms of the precise height of the plug relevant to the soil surface and the angle of the plant with some plants with broad leaf foliage having leaves being buried. A particular case in point is the necessity with lettuce plants to have the top of the plug level with the soil surface.
If the plug top is above the soil surface, evaporation and wicking occurs causing the plant plug to very rapidly dry out. If the plug top is below the soil surface, the soil then being in contact with or surrounding the stems and leaf area at the base of the plant will cause crown rot to set in with the loss of the plants.
Furthermore, planting often takes place in windy conditions resulting in plants blowing over in the wind before they are positioned correctly and enveloped with soil.
The objective therefore of the present invention is to provide improved machinery of the aforementioned type that is capable of transplanting seedlings from trays directly into ground planting positions, preferably with uniform ground spacing, and preferably constructed in a relatively uncomplicated manner. A further objective of the present invention is to provide improved devices for use in transplanting machinery of the aforementioned type.
Accordingly, the present invention provides apparatus for transplanting plugs comprising seedlings and propagating medium from a tray including a plurality of plug retaining cells into a prepared ground planting position, said apparatus including tray holding means, plug eject means for removing one or more plugs from the plug retaining cells, plug delivery means for receiving a plug ejected from said tray and delivering same via a travel path to a ground planting preparation device arranged to at least partly prepare said ground planting position, plug holding means associated with said ground planting preparation device arranged to hold a plug delivered by said plug delivery means, plant plug removal means arranged between said plug eject means and said plug holding means to remove any plant plug not containing a seedling viable for planting from said travel path prior to reaching said plug holding means, and plug planting means to move a said plug from said plug holding means to the prepared ground planting position in response to said apparatus having travelled a predetermined distance over the around.
Conveniently, the apparatus is constructed and operated so as to ensure that a seedling is always located at the seedling holding means when the seedling planting means is activated in response to the apparatus having travelled the predetermined distance. Preferably this might be achieved by providing at least one intermediate seedling holding device located along said travel path to interrupt and hold a seedling at said intermediate seedling holding device, the or each said intermediate seedling holding device including sensor means to determine if a seedling viable for planting is hold by the intermediate seedling holding device, and a said plant plug removal means located at or adjacent each said intermediate seedling holding device to remove from said travel path any plant plug not containing a seedling viable for planting. Conveniently the travel path might be formed by at least one substantially upright drop tube through which said seedlings pass while moving towards said seedling holding means associated with said ground planting preparation device, at least one said intermediate seedling holding device being located along the or each said drop tube. Preferably, at least one further sensor means may be located before the or each said intermediate seedling holding device to determine if a said plant plug contains a seedling viable for planting as said plant plug moves along said travel path. A further said plant plug removal means may be provided associated with the or each said further sensor means to remove from said travel path any said plant plug not containing a seedling viable for planting.
In one preferred embodiment, the seedling delivery means may include an endless conveyor having a plurality of plant plug receiving receptacles there along, each of said plant plug receiving receptacles being adapted to receive a plant plug ejected from a said seedling retaining cell of the tray, said endless conveyor being bodily movable from a position where one or more said seedling plant plugs are positioned in respective said plant receiving receptacles to a second position where said seedling plant plugs are sequentially released from said endless conveyor. Conveniently the bodily movement of the endless conveyor may be between 0xc2x0 and 60xc2x0 to 120xc2x0, preferably between 0xc2x0 and 90xc2x0. In a still further preferred embodiment, the tray holding means may be arranged to hold at least one tray in a substantially vertical orientation and includes tray indexing means to index the or each said tray downwardly a predetermined distance by one row of said seedling retaining cells each indexing movement, said seedling eject means being arranged to eject simultaneously a row of said seedling plant plugs to the seedling delivery means.
In accordance with a further aspect of the present invention, a seedling planting device is provided for use in planting seedlings into a prepared ground planting position, said seedling planting device being adapted to be mounted from transplanting apparatus capable of movement in a planting direction, said seedling planting device having a forward furrow forming member and a rearwardly located seedling plug holding region adapted to receive sequentially and hold seedlings with their associated seedling plug, and actuator means adapted to sequentially rearwardly eject said seedlings with their associated seedling plug into the furrow formed by said furrow forming member, said actuator means being actuated in response to said apparatus having travelled a predetermined distance in said planting direction, planting spacings being linearly constant along the ground. Preferably the linearly constant spacing being achieved regardless of ground speed variation controlled by a ground driven encoder and programmable microprocessor control with plant to plant distance being able to be changed and set by the operator while the machine is stationary or in motion. Preferably the holding region is formed by side walls of said device being angled toward one another in a downward direction to cooperate with and hold the seedling plug. Conveniently, the actuator means comprises a pusher member and an actuator, said actuator being arranged to reciprocally move said pusher member in a forward and rearward direction, said pusher member being arranged to move a said seedling plug rearwardly from said planting device when moved in a rearward direction. In a further preferred arrangement, the seedling planting device may also include a ski assembly having a forward portion extending forwardly of the furrow forming member and a rearward portion located laterally on either side of the furrow forming member, the ski assembly having an under surface which, in use, engages on the surface of the ground in which the seedlings are to be planted. Conveniently, the height of the ski assembly relative to the furrow forming member is adjustable. The ski assembly may be mounted whereby, in use, its height relative to the transporting apparatus can vary in response to changes in ground contour. The furrow forming member may be mounted whereby, in use, its height relative to the transplanting apparatus vanes in response to changes in ground contour.
In accordance with a still further aspect, the present invention provides apparatus for transplanting seedlings from a tray including a plurality of seedling retaining cells into a prepared ground planting position, said apparatus comprising tray holding means, seedling eject means for removing one or more seedlings from the seedling retaining cells, seedling delivery means for receiving a seedling ejected from a said tray and delivering same to a ground planting preparation device, said seedling delivery means including at least one seedling holding means having a sensor means associated therewith to determine if a seedling plug at said seedling holding means includes a live seedling viable for planting, said seedling holding means also including seedling plug eject means activated in response to said sensor means determining that a seedling plug at said seedling holding means does not contain a live seedling viable for planting. Preferably, the seedling delivery means includes re-orientation means and one or more drop tubes defining a travel path for said seedlings to the ground planting preparation device, said re-orientation means being arranged to reorientate seedlings ejected from a said tray such that the seedling plugs are directed downwardly when they enter a said drop tube.
According to another aspect, the present invention provides apparatus for transplanting seedlings from a tray including a plurality of seedling retaining cells into a prepared ground planting position, said apparatus comprising tray holding means, seedling eject means for removing one or more seedlings from the seedling retaining cells, seedling delivery means for receiving a seedling ejected from a said tray and delivering same to a ground planting preparation device, said seedling delivery means including an endless conveyor adapted, in a first position, to receive and hold a plurality of seedling plugs ejected from the seedling retaining cells of the tray, said endless conveyor being bodily movable from said first position to a second position where said seedling plugs are sequentially released at a release zone from said endless conveyor, and a first sensor means arranged to sense each said plant plug immediately after release from said endless conveyor to determine whether a live seedling viable for transplanting exists with said seedling plug. The apparatus may include a second sensor means associated with said endless conveyor to sense each said seedling plug conveyed by said endless conveyor to determine whether a live seedling viable for transplanting exists therewith, said second sensor means being located prior to release of the seedling plug from said endless conveyor. Preferably each said seedling plug released from said conveyor means is deposited in a delivery tube means with the plug directed downwardly, the delivery tube means extending to the ground planting preparation device. The seedling plug removal means may be provided at or adjacent an entrance zone of said delivery tube means to remove therefrom seedling plugs not containing a seedling viable for transplanting. In a further preferred embodiment, one or more intermediate seedling holding means for holding seedling plugs is provided part way along the length of the or each said delivery tube means. Preferably in a still further embodiment, a third sensor means is provided at the or each said intermediate seedling holding means to determine if a seedling viable for transplanting exists with each seedling plug held at the or each said intermediate seedling holding means, and eject means being provided associated with the intermediate seedling holding means to eject seedling plugs from said delivery tube means when the third sensor means establishes that a said seedling plug does not contain a seedling viable for transplanting.
In a still further preferred embodiment, the endless conveyor may include a plurality of adjacent transverse extending receptacles open at both ends and adapted to retain a said seedling plug therein after being ejected from a seedling retaining cell of a said tray, each said receptacle being formed by a belt portion of the endless conveyor and wall portions laterally extending from said belt portion, each said wall portion having a T-shape in cross-section providing a plurality of spaced retaining bars spaced from said belt portion. The release zone may be defined by said belt portion passing around roller means of a diameter sufficient to open the distance between the adjacent retaining bars to allow the seedling plugs to be released from the endless conveyor. The belt portion may be moved in discreet steps, the distance of each said step being equal to the plug cell width, at a speed sufficient to move said seedling plugs laterally away from the conveyor means at said release zone. Conveniently, at said first position, both ends of each said receptacle are open and at said second position, a movable member traverses a lower end of the receptacles so as to retain the seedling plugs therein until the release zone is reached.
In another preferred embodiment, the endless conveyor may include a plurality of transverse extending receptacles to retain a said seedling plug therein after being ejected from a seedling retaining cell of a said tray, said endless conveyor having a plurality of spaced teeth formations on an inner surface co-operable with complimentary shaped formations on an indexing member, said indexing member being moved in a forward direction and a reverse direction by actuator means whereby in a forward direction said indexing member engages with the teeth formations on one length of said endless conveyor and in the reverse direction, said indexing member engages with the teeth formations on a second length of said endless conveyor opposite to said one length. The indexing member may be moved laterally towards said second length and away from said one length, and vice versa, when the indexing member is respectively moved in the reverse and the forward directions.
In another aspect the present invention also provides a tray indexing arrangement for use in apparatus for transplanting seedlings from cells within a tray to a ground planting position, said tray indexing arrangement comprising a guide frame support to enable a seedling tray to be supported substantially vertically with the seedlings disposed substantially horizontally, said guide frame support permitting the tray to move in a downward direction past a seedling eject mechanism, and a tray indexing mechanism including at least one sprocket wheel having teeth adapted to engage with indexing formations on the tray, the sprocket wheel or wheels being driven by an indexing device having a rotatable control wheel with a plurality of spaced control pins each adapted to pass through a cam guide track of a pivoting arm during at least part of the movement of the control wheel, said control wheel being rotatable under the influence of the weight of a said seedling tray moving downward in said guide frame support until a said control pin engages with a stop zone of the cam guide track of said pivoting arm indicative of the seedling tray reaching a position where one or more seedlings can be ejected therefrom by said seedling eject mechanism, and an actuator means provided to move said arm to release the control pin from the stop zone of the cam guide track when a further indexing step is required.